Lock for an oil field valve

Abstract

An anti-theft lock for oilfield valves where a base member fits over and attaches to a valve so that the valve stem projects outwardly of the base member. A cover member has pins received in locking bores in the base member where independent keys operate independent locks to lock the cover member to the base member.

What is claimed is: 
     
       1. A locking device for oil field valves or the like including: a lock base member having a recessed portion extending from a bottom surface of the base member, said recessed portion being configured to fit over a valve flange and to a body of a valve, an opening in said base member extending through said base member so that when the base member is located on a valve body, a valve stem of a valve can project through the base member and be manipulated with the base member in position on a valve body, at least two first locking bores extending downwardly from an upper surface of said base member, at least two second locking bores extending inwardly from the respective sides of said base member and partially intersecting said locking bores;   means for affixing a base member onto a valve body;   a lock cover member having a lower surface adapted for complimentary engagement with the upper surface of the base member;   at least two locking pin members attached to said lock cover member and extending downwardly from the lower surface of said cover member, each of said pin members having semi-cylindrical recesses to align with said second bores;   said lock cover member having recessed portions extending upwardly from said lower surface to internally receive said locking pin members, the valve stem of a valve, and the means which interconnect the cover member, base member and valve body; and   keying and locking means in each of said second locking bores including cylindrical locking members with semi-cylindrical recesses to align with said first bore and rotatively movable into and out of engagement with said locking pin members for releasably interconnecting said cover member to said base member so that said cover member can be removed relative to said base member to permit access to the valve stem of a valve and can be interconnected to said base member and enclose said locking pin members, the valve stem and the bolt heads on the bolt means.   
     
     
       2. The apparatus as set forth in claim 1 wherein said lock base member has an attached, upwardly extending connection pin member extending upwardly from the upper surface of said base member through an aligned opening in said lock cover member, said connection pin member extending above the upper surface a distance sufficient for permitting said lock cover member to be displaced upwardly and away from a valve stem thereby permitting access to a valve stem without disconnection of the lock base member and lock cover member. 
     
     
       3. The apparatus as set forth in claim 2 including a stop means on said connection pin member for limiting upward travel of the lock cover member. 
     
     
       4. The apparatus as set forth in claim 1 wherein said keying and locking means are respectively keyed to utilize different key members.